Communication system using OFDM for one direction and DSSS for another direction

Abstract

A method and apparatus for wireless communication are described. In one embodiment, a method for communicating with a subscriber comprises transmitting orthogonal frequency domain multiplexing (OFDM) signals to the subscriber, and receiving direct-sequence spread spectrum (DSSS) signals from the subscriber.

1. A method comprising:
 transmitting orthogonal frequency division multiplexing (OFDM) signals, the OFDM signals comprising OFDM modulation according to an OFDM only modulation technique; 
 receiving a direct-sequence spread spectrum (DSSS) signal generated by a subscriber, the DSSS signal comprising DSSS modulation according to a DSSS only modulation technique; and 
 enabling use of a first portion of OFDM subcarriers of said OFDM signals by the subscriber using said received DSSS signal. 
 
     
     
       2. The method of  claim 1 , wherein said receiving said DSSS signal comprises:
 establishing a bi-directional DSSS communication link with the subscriber. 
 
     
     
       3. The method of  claim 2 , further comprising:
 establishing a uni-directional OFDM communication link using said first portion of OFDM subcarriers. 
 
     
     
       4. The method of  claim 3 , wherein said bi-directional DSSS communication link and said uni-directional OFDM communication link comprise a same communication service. 
     
     
       5. The method of  claim 1 , wherein said enabling use of said first portion of said OFDM subcarriers comprises:
 transmitting a signal to the subscriber. 
 
     
     
       6. A method comprising:
 transmitting orthogonal frequency division multiplexing (OFDM) signals, the OFDM signals comprising OFDM modulation according to an OFDM only modulation technique; 
 establishing a bi-directional direct-sequence spread spectrum (DSSS) communication link with a subscriber, DSSS signals of the DSSS communication link comprising DSSS modulation according to a DSSS only modulation technique; and 
 enabling use of at least a portion of said OFDM signals by the subscriber using communication via said bi-directional DSSS communication link, wherein said use of said at least a portion of said OFDM signals provides a uni-directional OFDM link. 
 
     
     
       7. The method of  claim 6 , wherein said bi-directional DSSS communication link and said uni-directional OFDM link comprise a same communication service. 
     
     
       8. The method of  claim 6 , further comprising:
 transmitting signals for controlling said bi-directional DSSS communication link as DSSS signals in said bi-directional DSSS communication link; and 
 transmitting signals for controlling said uni-directional OFDM communication link as OFDM signals in said uni-directional OFDM communication link. 
 
     
     
       9. The method of  claim 6 , wherein said bi-directional DSSS communication link comprises a frequency division duplex (FDD) communication link, and wherein said uni-directional OFDM communication link occupies different spectrum than said DSSS communication link. 
     
     
       10. A method comprising:
 establishing a bi-directional direct-sequence spread spectrum (DSSS) communication link with a subscriber, wherein DSSS signals of the DSSS communication link comprise DSSS modulation according to a DSSS only modulation technique; and 
 establishing a uni-directional orthogonal frequency division multiplexing (OFDM) link with the subscriber, wherein OFDM signals of the OFDM communication link comprise OFDM modulation according to an OFDM only modulation technique, and wherein said bi-directional DSSS communication link and said uni-directional communication link are part of a same communication service. 
 
     
     
       11. The method of  claim 10 , wherein said establishing said uni-directional OFDM link comprises:
 enabling use of at least a portion of transmitted OFDM signals by the subscriber using communication via said bi-directional DSSS communication link. 
 
     
     
       12. The method of  claim 10 , further comprising:
 transmitting signals for controlling said bi-directional DSSS communication link as DSSS signals in said bi-directional DSSS communication link; and 
 transmitting signals for controlling said uni-directional OFDM communication link as OFDM signals in said uni-directional OFDM communication link. 
 
     
     
       13. A method comprising:
 establishing a bi-directional DSSS communication link between a subscriber and a base station, wherein DSSS signals of the DSSS communication link comprise DSSS modulation according to a DSSS only modulation technique; 
 using said bi-directional DSSS communication link to communicate information for use in establishing an orthogonal frequency division multiplexing (OFDM) communication link for use by the subscriber; and 
 establishing a uni-directional OFDM communication link with the subscriber using said DSSS communication link, wherein OFDM signals of the OFDM communication link comprise OFDM modulation according to an OFDM only modulation technique. 
 
     
     
       14. The method of  claim 13 , wherein said bi-directional DSSS communication link and said uni-directional OFDM link comprise a same communication service. 
     
     
       15. The method of  claim 13 , wherein said establishing said uni-directional OFDM link comprises:
 enabling use of at least a portion of transmitted OFDM signals by the subscriber using communication via said bi-directional DSSS communication link. 
 
     
     
       16. A system comprising:
 a subscriber having
 a DSSS transmitter, 
 a DSSS receiver; and 
 an OFDM receiver; 
 
 a communication network communicably coupled with the subscriber, the communication network having
 a DSSS receiver, 
 a DSSS transmitter; and 
 an OFDM transmitter, and 
 
 a communication service protocol operable to establish a bi-directional communication link for use by the subscriber using said DSSS transmitters and DSSS receivers and a uni-directional communication link for use by the subscriber using said OFDM receiver and OFDM transmitter, wherein DSSS signals of the DSSS communication link comprise DSSS modulation according to a DSSS only modulation technique, and wherein OFDM signals of the OFDM communication link comprise OFDM modulation according to an OFDM only modulation technique. 
 
     
     
       17. A method comprising:
 transmitting orthogonal frequency division multiplexing (OFDM) signals; 
 receiving a plurality of direct-sequence spread spectrum (DSSS) signals generated by a plurality of subscribers, wherein the plurality of DSSS signals are transmitted asynchronously; and 
 enabling use of a first portion of OFDM subcarriers of said OFDM signals by the subscribers using a respective DSSS signal of said received DSSS signals.